A leak on a patio roof connection can spoil the enjoyment of your screen room or sunroom. Most of the leaking roofs we see have little to no slope. Usually less than 1/2 ” per foot as is required minimum on most metal patio roof panels. Insufficient slope will cause your own gutter system and spouts to force water into parts of your patio roof that are not designed to hold water. If trees are located nearby in these patios with low slope they almost always have leak problems. Sometimes you can remove your gutter and spouts completely and improve but not eliminate the problem.
We find many roofs leak near the edge without homeowners being aware. Many contractors improperly installed the drip edge over the felt and almost always eventually causes a roof leak. Flashing to an existing roof is best if you go up to 3-4 shingles. This moves the flashing above that problem area. When contracting your patio make sure to get details of how your contractor plans to tie in your new patio roof to your existing roof. Many contractors do not include this important method of connecting to your roof.